Updated openstack/openstack
Project: openstack/keystone  d6ae284c3a0e175f5b9627cbe8ca0a3b6213d74e
null
Enhance tests for delete_grant no user/group

There were no tests to show that when delete a grant and the
target user or group doesn't exist then it fails with NotFound.

Part of bp use-common-oslo-db-code

Change-Id: I4b927bc234621ef164d0e2ebb594b47406699975